Woolly Cupgrass (Eriochloa villosa) Control in Corn (Zea mays) with Chloroacetamide Herbicides

Woolly cupgrass control with acetochlor, alachlor, and metolachlor in corn was evaluated at Stratford, IA from 1985 through 1990. Averaged over application techniques, acetochlor at 3.4 kg/ha controlled more than 85% of woolly cupgrass five out of six years, whereas alachlor at 4.5 kg/ha and metolachlor at 3.4 kg/ha controlled more than 85% of this weed one and two years out of six, respectively. Herbicide incorporation did not consistently improve woolly cupgrass control. PRE applications were more effective than incorporated treatments in years with greater than 7 mm rainfall occurring within 3 d after application.